oj.uz

Submission #606800

# Submission time Handle Problem Language Result Execution time Memory
606800 2022-07-26T08:34:32 Z ThMinh_ Network (BOI15_net) C++14
63 / 100
 674 ms 262144 KB 
#include<bits/stdc++.h>
#define forin(i,a,b) for(int i=a;i<=b;++i)
#define forv(a,b) for(auto &a:b)
#define ii pair<int, int>
using namespace std;
const int N = 5e5+10;
int n, m, cnt, tim, root;
int low[N], num[N], color[N], vis[N], id[N];
vector<int> loop[N], ke[N];
vector<ii> adj[N], ans;
stack<int> st;
void anal(int u, int edad) {
	low[u] = num[u] = ++tim;
	vis[u] = 1; st.push(u);
	forv(e, adj[u]) {
		int v = e.first, eid = e.second;
		if(edad == eid) continue;
		if(!vis[v]) {
			anal(v, eid);
			low[u] = min(low[u], low[v]);
		}
		else if(vis[v] == 1) low[u] = min(low[u], num[v]);
	}
	if(low[u] == num[u]) {
		int v; cnt++;
		do {
			v = st.top(); st.pop();
			loop[cnt].push_back(v);
			id[v] = cnt;
			vis[v] = 2;
		} while(v != u);
	}
}
queue<int> dfs(int u) {
	color[u] = 1;
	queue<int> res;
	if(ke[u].size() == 1) {res.push(u); return res;}
	forv(v, ke[u]) if(!color[v]) {
		queue<int> q = dfs(v);
		if(res.size() + q.size() > 2 && res.size() > 0 && q.size() > 0) {
			ans.push_back({res.front(), q.front()});
			res.pop(); q.pop();
		}
		while(!q.empty()) {res.push(q.front()); q.pop();}
	}
	return res;
}
int main () {
	cin.tie(0)->sync_with_stdio(0);
	if(fopen("Task.inp","r")) {
		freopen("Task.inp","r",stdin);
		freopen("WA.out","w",stdout);
	}
	if(fopen("BlueHouse.inp","r")) {
		freopen("BlueHouse.inp","r",stdin);
		freopen("BlueHouse.out","w",stdout);
	}
	cin>>n;
	m = n - 1;
	forin(i,1,m) {
		int u, v; cin>>u>>v;
		adj[u].push_back({v, i});
		adj[v].push_back({u, i});
	}
	anal(1, 0);
	if(cnt == 2) {
		cout<<1<<"\n"<<loop[1].back()<<" "<<loop[2].back();
		return 0;
	}
	forin(i,1,cnt) {
		forv(u, loop[i]) {
			forv(v, adj[u]) if(id[v.first] != i) {
				ke[i].push_back(id[v.first]);
			}
		}	
	}
	queue<int> slt;
	forin(i,1,cnt) if(ke[i].size() > 1) {slt = dfs(i); root = i; break;}
	if(slt.size() == 2) {root = slt.front(); slt.pop();}
	if(slt.size() == 1) ans.push_back({root, slt.front()});
	cout<<ans.size()<<"\n";
	forv(v, ans) cout<<loop[v.first].back()<<" "<<loop[v.second].back()<<"\n";
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:51:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |   freopen("Task.inp","r",stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
net.cpp:52:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |   freopen("WA.out","w",stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
net.cpp:55:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   55 |   freopen("BlueHouse.inp","r",stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
net.cpp:56:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |   freopen("BlueHouse.out","w",stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 35540 KB Output is correct
2 Correct 18 ms 35580 KB Output is correct
3 Correct 18 ms 35540 KB Output is correct
4 Correct 18 ms 35540 KB Output is correct
5 Correct 17 ms 35556 KB Output is correct
6 Correct 20 ms 35584 KB Output is correct
7 Correct 17 ms 35540 KB Output is correct
8 Correct 19 ms 35536 KB Output is correct
9 Correct 19 ms 35540 KB Output is correct
10 Correct 18 ms 35512 KB Output is correct
11 Correct 18 ms 35540 KB Output is correct
12 Correct 21 ms 35520 KB Output is correct
13 Correct 22 ms 35492 KB Output is correct
14 Correct 20 ms 35460 KB Output is correct
15 Correct 17 ms 35548 KB Output is correct
16 Correct 19 ms 35472 KB Output is correct
17 Correct 18 ms 35584 KB Output is correct
18 Correct 17 ms 35540 KB Output is correct
19 Correct 20 ms 35584 KB Output is correct
20 Correct 20 ms 35520 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 35540 KB Output is correct
2 Correct 18 ms 35580 KB Output is correct
3 Correct 18 ms 35540 KB Output is correct
4 Correct 18 ms 35540 KB Output is correct
5 Correct 17 ms 35556 KB Output is correct
6 Correct 20 ms 35584 KB Output is correct
7 Correct 17 ms 35540 KB Output is correct
8 Correct 19 ms 35536 KB Output is correct
9 Correct 19 ms 35540 KB Output is correct
10 Correct 18 ms 35512 KB Output is correct
11 Correct 18 ms 35540 KB Output is correct
12 Correct 21 ms 35520 KB Output is correct
13 Correct 22 ms 35492 KB Output is correct
14 Correct 20 ms 35460 KB Output is correct
15 Correct 17 ms 35548 KB Output is correct
16 Correct 19 ms 35472 KB Output is correct
17 Correct 18 ms 35584 KB Output is correct
18 Correct 17 ms 35540 KB Output is correct
19 Correct 20 ms 35584 KB Output is correct
20 Correct 20 ms 35520 KB Output is correct
21 Correct 18 ms 35512 KB Output is correct
22 Correct 18 ms 35780 KB Output is correct
23 Correct 17 ms 35796 KB Output is correct
24 Correct 20 ms 35812 KB Output is correct
25 Correct 20 ms 35796 KB Output is correct
26 Correct 18 ms 35792 KB Output is correct
27 Correct 19 ms 35848 KB Output is correct
28 Correct 21 ms 35752 KB Output is correct
29 Correct 21 ms 35796 KB Output is correct
30 Correct 17 ms 35540 KB Output is correct
31 Correct 19 ms 35796 KB Output is correct
32 Correct 18 ms 35528 KB Output is correct
33 Correct 17 ms 35540 KB Output is correct
34 Correct 18 ms 35540 KB Output is correct
35 Correct 20 ms 35572 KB Output is correct
36 Correct 18 ms 35540 KB Output is correct
37 Correct 18 ms 36052 KB Output is correct
38 Correct 21 ms 36372 KB Output is correct
39 Correct 18 ms 35508 KB Output is correct
40 Correct 18 ms 35540 KB Output is correct
41 Correct 17 ms 35540 KB Output is correct
42 Correct 18 ms 35668 KB Output is correct
43 Correct 19 ms 35668 KB Output is correct
44 Correct 19 ms 35492 KB Output is correct
45 Correct 21 ms 35588 KB Output is correct
46 Correct 17 ms 35668 KB Output is correct
47 Correct 17 ms 35540 KB Output is correct
48 Correct 17 ms 35528 KB Output is correct
49 Correct 18 ms 35856 KB Output is correct
50 Correct 16 ms 35540 KB Output is correct
51 Correct 17 ms 35584 KB Output is correct
52 Correct 18 ms 35796 KB Output is correct
53 Correct 20 ms 35996 KB Output is correct
54 Correct 19 ms 35540 KB Output is correct
55 Correct 24 ms 35660 KB Output is correct
56 Correct 21 ms 35472 KB Output is correct
57 Correct 21 ms 35568 KB Output is correct
58 Correct 21 ms 35844 KB Output is correct

Subtask #3
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 35540 KB Output is correct
2 Correct 18 ms 35580 KB Output is correct
3 Correct 18 ms 35540 KB Output is correct
4 Correct 18 ms 35540 KB Output is correct
5 Correct 17 ms 35556 KB Output is correct
6 Correct 20 ms 35584 KB Output is correct
7 Correct 17 ms 35540 KB Output is correct
8 Correct 19 ms 35536 KB Output is correct
9 Correct 19 ms 35540 KB Output is correct
10 Correct 18 ms 35512 KB Output is correct
11 Correct 18 ms 35540 KB Output is correct
12 Correct 21 ms 35520 KB Output is correct
13 Correct 22 ms 35492 KB Output is correct
14 Correct 20 ms 35460 KB Output is correct
15 Correct 17 ms 35548 KB Output is correct
16 Correct 19 ms 35472 KB Output is correct
17 Correct 18 ms 35584 KB Output is correct
18 Correct 17 ms 35540 KB Output is correct
19 Correct 20 ms 35584 KB Output is correct
20 Correct 20 ms 35520 KB Output is correct
21 Correct 18 ms 35512 KB Output is correct
22 Correct 18 ms 35780 KB Output is correct
23 Correct 17 ms 35796 KB Output is correct
24 Correct 20 ms 35812 KB Output is correct
25 Correct 20 ms 35796 KB Output is correct
26 Correct 18 ms 35792 KB Output is correct
27 Correct 19 ms 35848 KB Output is correct
28 Correct 21 ms 35752 KB Output is correct
29 Correct 21 ms 35796 KB Output is correct
30 Correct 17 ms 35540 KB Output is correct
31 Correct 19 ms 35796 KB Output is correct
32 Correct 18 ms 35528 KB Output is correct
33 Correct 17 ms 35540 KB Output is correct
34 Correct 18 ms 35540 KB Output is correct
35 Correct 20 ms 35572 KB Output is correct
36 Correct 18 ms 35540 KB Output is correct
37 Correct 18 ms 36052 KB Output is correct
38 Correct 21 ms 36372 KB Output is correct
39 Correct 18 ms 35508 KB Output is correct
40 Correct 18 ms 35540 KB Output is correct
41 Correct 17 ms 35540 KB Output is correct
42 Correct 18 ms 35668 KB Output is correct
43 Correct 19 ms 35668 KB Output is correct
44 Correct 19 ms 35492 KB Output is correct
45 Correct 21 ms 35588 KB Output is correct
46 Correct 17 ms 35668 KB Output is correct
47 Correct 17 ms 35540 KB Output is correct
48 Correct 17 ms 35528 KB Output is correct
49 Correct 18 ms 35856 KB Output is correct
50 Correct 16 ms 35540 KB Output is correct
51 Correct 17 ms 35584 KB Output is correct
52 Correct 18 ms 35796 KB Output is correct
53 Correct 20 ms 35996 KB Output is correct
54 Correct 19 ms 35540 KB Output is correct
55 Correct 24 ms 35660 KB Output is correct
56 Correct 21 ms 35472 KB Output is correct
57 Correct 21 ms 35568 KB Output is correct
58 Correct 21 ms 35844 KB Output is correct
59 Correct 646 ms 96564 KB Output is correct
60 Correct 674 ms 100792 KB Output is correct
61 Correct 17 ms 35540 KB Output is correct
62 Correct 18 ms 35584 KB Output is correct
63 Correct 526 ms 88200 KB Output is correct
64 Correct 25 ms 39940 KB Output is correct
65 Correct 49 ms 56068 KB Output is correct
66 Correct 249 ms 194076 KB Output is correct
67 Runtime error 667 ms 262144 KB Execution killed with signal 9
68 Halted 0 ms 0 KB -